Solution:
A) Charge cannot exist without mass but mass can exist without charge: This statement is true. A charge is always associated with mass. In other words, any object that has a charge will also have mass. However, there are particles, such as neutrinos, that have mass but no charge.
B) Charge is invariant but mass varies with velocity: This statement is also true. A charge is an intrinsic property of a particle and does not depend on its velocity. On the other hand, the mass of a particle increases with its velocity according to the theory of relativity.
C) Charge is conserved but mass alone may not be conserved: This statement is true as well. A charge is a conserved quantity in the universe, which means that the total charge in a closed system remains constant over time. However, mass is not always conserved. It can be converted into energy and vice versa, as described by Einstein's famous equation E=mc^2.
